What sound do you have? The integrated (on the motherboard) sound or a separate SoundBlaster sound card?
When you say "download" do you mean "download" from the Dell drivers download or do you mean "install" on the PC? (some mistakenly call installing "download" and the reason I ask).
When you download, DO NOT use the Dell download manager - it has problems - just download direct. HERE is the Analog Devices ADI 198X driver and when I click on "Downlaod" it downloads without a problem.
Dimension E510 with D925 CPU and Vista Home Premium 32 bit
Home Built PC with Q6600 CPU, 8GB RAM, HD4850 Video, HTO Striker 7.1 Audio Card - Windows 7 64 bit Professional
Sonar 8.5.1 ( Producer) DAW Software/Focusrite Saffire Pro 40 Recording Interface and Frontier Tranzport wireless controller.